Acne is a condition of the human skin characterized by an excess flow of sebum, or skin oil, from the sebaceous glands located in the pilosebaceous apparatus. Sebum reaches the skin surface through the duct of the hair follicle. The presence of excessive amounts of sebum in the duct and on the skin acts to block or stagnate the continuous flow of sebum from the follicular duct, thus producing a thickening and a solidification of the sebum to form a solid plug known as a comedone. When this process occurs, hyperkeratinization of the follicular opening is stimulated, thus completely closing the duct. The usual results are papules, pustules, or cysts, often contaminated with bacteria which cause secondary infections. Acne is particularly characterized by the presence of comedones, inflammatory papules, pustules, or cysts. The effect of acne ranges from slight skin irritation and pitting to disfiguring scars.
Many topical therapeutic agents are employed in the treatment of acne and seborrhea to prevent the blocking of the follicular duct, to reopen the duct once it has become blocked, to act against the infecting bacteria or the thickened sebum, and to provide combinations of each of these actions. The horny outer layer of the skin, which is known as the stratum corneum, is formed of dead cells composed largely of keratin. Therapeutic agents which act to prevent the blocking of the follicular duct by promoting the removal or sloughing off of excess keratin are known as keratolytic agents.
Benzoyl peroxide has been used as a keratolytic agent and an antibacterial agent in the topical treatment of skin lesions such as acne, seborrhea, burns, varicose ulcers, skin irritations, and sycosis vulgaris. See e.g., Levine et al., Ohio State Med. J., 65, 492 (1969); U.S. Pat. No. 3,535,422, to Cox et al., issued Oct. 20, 1970; British Patent Application Nos. 1,185,685, to Fisher, published Mar. 25, 1970; 1,163,004, to Stiefel Laboratories, Inc., published Sep. 4, 1969; and 1,407,937, to Stiefel Laboratories, Inc. published Oct. 1, 1975. As noted, benzoyl peroxide has been used as a very effective keratolytic and antibacterial agent in the treatment of acne. The topical application of benzoyl peroxide for skin lesion therapy is thoroughly detailed in the medical literature. See Brogdne et al., Drugs, 4, 417 (1974); Poole et al., Arch Derm., 102, 400 (1972); Eaglstein, Arch Derm., 97, 527 (1968); Pace, Can Med. Assoc. J., 93,252 (1965); Vasarinsh, Arch. Derm., 98, 183 ( 1968); Mysliborski et al., AFP, 15, 86 (1977); Nare, Br. J. Clin. Prac, 29, 63 (1975); Fulton et al., Arch. Derm., 1, 10, 83 (1974); and Wilkinson et al., Can. Med. Assoc. J., 95, 28 (1966).
While benzoyl peroxide is an effective topical agent for the treatment of skin lesions such as appear in acne, seborrhea, and other conditions, it has the undesirable side effect of being a contact irritant. The irritation associated with benzoyl peroxide therapy has also been detailed in the medical literature cited in the previous paragraph. Additionally, the redness induced by benzoyl peroxide may impair a patient's ability to perceive the improvement in acne condition initially. Accordingly, some patients are denied the benefits of benzoyl peroxide therapy because of the irritation problem. When used in the treatment of acne, benzoyl peroxide produces dryness, exfoliation, increased redness and a decrease in bacterial flora.
It has been surprisingly found in the present invention that highly efficacious compositions which are non-irritating or less irritating to the skin are achieved when the benzoyl peroxide is utilized in conjunction with at least one other compound selected from the group consisting of panthenol, pantothenic acid, pantotheine, pantothine, C1-C30 alkyl esters of panthothenic acid, C1-C30 carboxylic acid esters of panthenol, C1-C30 alkyl ethers of panthenol, tocopherol, C1-C30 carboxylic acid esters of tocopherol, zinc oxide, allantoin, and mixtures thereof. Because these compositions are non-irritating or less irritating to the skin and reduce skin redness, these compositions have the advantage of inducing compliance to a treatment regimen. Consequently, because of the higher likelihood of user compliance, there is increased likelihood of successful treatment of the acne or other skin lesions.
It is therefore an object of the present invention to provide dermatological compositions for the treatment of acne and other skin lesions in humans.
It is another object of the present invention to provide dermatological compositions for the treatment of acne and other skin lesions in humans which are non-irritating or less irritating, and reduce redness better, than benzoyl peroxide alone.
It is another object of the present invention to provide methods for the treatment of acne and other skin lesions in humans.
It is another object of the present invention to provide methods of the treatment of acne and other skin lesions in humans whereby the methods are non-irritating or less irritating to the user, and reduce redness better, than benzoyl peroxide alone.
These and other objects of this invention will become apparent in light of the following disclosure.